It is known to use argon and other inert gassing when welding; such gasses protect the molten metal from the effect of atmospheric gasses such as oxygen. Such inert gasses are provided in large gas cylinders; typical industrial mobile welding appliances make use of cylinders whose mass when full is typically in the region of 86 kilograms. Replacing these cylinders represents a manual handling risk; generally, it is required to remove the empty cylinder from a platform on the welding appliance to be stored for refilling and subsequently lifting a new full cylinder onto to the platform. This manual handling task has been assessed as an exceptionally high risk (Postural Loading (Handler) Whilst Manually Lifting and Lowering a Gas Cylinder, Dawn Groves, University of Bradford, available online at: http://gasgrab.com/Bfd%20Uni%20Full%20Project.pdf).
Various means have been proposed for dealing with this problem. The United Kingdom Patent Application published as GB 2 407 529 provides one or two handles that fit onto a gas cylinder; this still requires manual lifting by a user. Various trolley-based solutions have been proposed, generally involving a platform that is raised by a winch or by hydraulic means; see, for example, the European Patent Application published as EP 1 988 000. However, such devices still need the cylinder to be manually shuffled between the platforms of the trolley and the welding apparatus.